Spring hinge for bracelets, watch bands, and the like



May 10, 1955 E POPPER 2,707,800

SPRING HINGE FOR BRACELETS, WATCH BANDS AND THE LIKE Filed Aug. 16, 1954 INVENTOR EMIL POPPER.

BY W

ATTORNEY United States Patent SPRING HINGE FOR BRACELETS, WATCH BANDS, AND THE LIKE Emil Popper, Brooklyn, N. Y.

Application August 16, 1954, Serial No. 449,973

6 Claims. (Cl. 16-180) This invention relates to a spring hinge for bracelets, watch bands and the like.

Conventional spring hinges for bracelets, wrist watch bands and straps and the like generally comprise cooperative hinge members, a pin interengaging said hinge members and serving as a pintle therefor, and a torsion spring acting between said hinge members to provide spring action therebetween. This type of construction has its drawbacks and disadvantages. It is not an easy matter to hold the pins securely in place for long periods of continual use and even abuse, especially since it is also required that these pins be made removable for repair and replacement purposes and the like. Consequently, it is frequently the case that the pins become dislodged or loose and even lost. It is also frequently the case that the torsion springs break or lose their tension. The materials of which the pins and torsion springs are normally made do not strongly resist corrosion in the presence of perspiration and moisture. Furthermore, there are the practical disadvantages attendant upon the installation and removal of these pins and springs. In many cases, removal of the pins necessitates destruction of the springs.

It is the principal object of this invention to provide a spring-type hinge for bracelets, wrist watch bands and other uses, in which there is no pintle in the commonly accepted sense of the term, and no torsion spring in the commonly accepted use of the term, but which nonetheless possesses pivotal or hinging means involving torsional spring forces.

Briefly stated, the present device is provided with hinge members, preferably one connected to one part of a bracelet and a pair flanking the first hinge member and connected to another part of the bracelet or toa watch casing. Registering holes are formed in these three hinge members, square in cross section. A pair of spring bars, generally triangular in cross section, are inserted into these registering holes. These triangular spring bars are disposed face to face to form a square adapted to fit snugly into the square hole of the first mentioned hinge member. The ends of these two spring'bars project into the other two hinge members. The facing sides of the ends of the two spring bars are tapered off so as to provide a space between them. When the first hinge member is pivoted relative to the second mentioned hinge members, the spring bars turn integrally with said first hinge member since they are snugly fitted therein, and they turn relative to the second mentioned hinge members. Such. being the case, the tapered ends of said spring bars ride up on the sides of the square holes in said second mentioned hinge members and are thereby squeezed or flexed toward each other. Since these spring bars are made of spring metal, this flexing movement takes place against their inherent spring tension and tensional resistance to the pivotal movement of the two second mentioned hinge members isthereby efiected.

It will be apparent from theforegoing, that the two spring bars above mentioned serve not only as. pintles,

without actually constituting pintles, but also as torsion springs, without actually comprising or constituting torsion springs. In other words, these spring bars perform the function of a pintle and the function of a torsion spring without actually constituting either a pintle or a torsion spring.

It will be apparent from the foregoing that the tor, sional resistance to the pivotal movement above described extends over an angular distance of approximately 45- degrees. Beyond that point, the spring action no longer opposes the pivotal movement but instead favors it and helps it along. When the pivotal movement continues for a full degrees a locking action is experienced since the two spring bars are now able to spring back to their original unstressed positions. It is accordingly another object of this invention to provide a spring lock in a hinge of the character described which tensionally and resiliently tends to hold the hinge parts against relative pivotal movement.

An important feature of this invention is the fact that the spring bars may be made of the same or substantially the same material as the hinge members themselves. For example, they may all bemade of non-corrosive stainless steel or gold, alloyed to provide resistance to abrasion and also to provide spring action.

The invention is illustrated in the accompanying drawing in which:

Fig. 1 is a side view of a wrist watch bracelet, including a wrist watch, embodying a pair of spring hinges as herein described and claimed.

Fig. 2 is a top view of said bracelet and wrist watch, showing the components of one of said hinges in exploded relationship.

Fig. 3 is a section on the line 3-3 of Fig. 2, being a longitudinal section through the other of said hinges.

Fig. 4 is a transverse section on the line 4-4 of Fig. 2, showing the hinge in unflexed state.

Fig. 4A is. a view similar to that of Fig. 4 but showing the hinge in flexed state.

Fig. 5 is a transverse section on the line 5-5 of Fig. 2, this view being equally appropriate whether the hinge is flexed or not.

Wrist watch 10 shown in the drawing is intended to be of conventional construction for the purpose of illustrating the invention. In the illustrated form of the invention, a pair of arcuate bracelet arms 12 and 14 are provided to engage the wrist of the wearer and thereby to support the wrist watch thereon. These arcuate bracelet arms are pivotally connected to said wrist.

watch and they are movable from their solid line posi-- tionsto their dotted line positions and vice versa in order to provide for ingress and egress of the wrist. Consequently, pivotal connections must be providedbetween said arcuate arms and the wrist watch. Further,- more, it is essential that the two arcuate arms be spring urged or biased toward each other in order to provide tensioned, engagement with the wrist to hold the wrist. watch thereon in normal position. Consequently, spring means must be provided between said arcuate arms and said wrist watch.

It will be observed that Wrist watch 10 is provided with a plurality of cars 16, a pair on each side of the watch, in spaced parallel relation to each other. to these ears are tubular members or sleeves 18. The holes in each pair of ears are formed in registration with each other and these sleeves 18 are therefore held in axial alignment with each other, the axis of each pair of these sleevesbeingparallel to the axis of the other pair. It will be noted in Fig. 4 that a hole 20 is for-med in.

being square in cross section.

Patented May 10, 1955' Secured four corners of hole 20 define 90 degree angles and all four sides of said hole 20 are dimensionally equal.

Sleeves 13 are relatively short in length and the spacing between them is suflicient to receive a relatively long sleeve 22. There is one such sleeve 22 between each pair of short sleeves 18. It will now be seen that sleeves 22 are fixedly secured to the arcuate bracelet arms 12 and 14. As has above been indicated, sleeves 18 are fixedly secured to the wrist watch proper. It will be clear, therefore, that any pivotal action that might take place between the arcuate arms and the wrist watch would involve relative angular movement between sleeves 18 on the one hand and sleeves 22 on the other hand.

Sleeves 18 and 22 are shown to be cylindrical in outside or external shape. This is preferred but not essential to the functioning of the present invention. It will also be noted that sleeves 18 and 22 are equal in outside diameter and this, too, is preferred but not essential. Extending lengthwise through each sleeve 22 is a square hole 24 corresponding in dimensions to square hole 20 of sleeves 18. When the several parts thus far described are assembled, holes 24 and 20 are brought into axial alignment with each other. Holes 24 extend completely through sleeves 22. This is equally true of holes 20 in sleeves 18 but caps 28 are affixed to sleeves 18 on the outer ends thereof to close off said holes 26. When the watch and bracelet herein described and claimed are assembled, caps 28 conceal both holes 20 and 24 and also the contents of said holes, as hereinafter described.

Disposed within each sleeve 22 is a pair of spring bars 30 which are shown in Figs. 2 to inclusive. Spring bars 30 project outwardly at both ends from sleeve 22 and into sleeves 18 as Fig. 3 clearly shows. It will be observed in Fig. 5 that the main body or central portion of each spring bar 30 is triangular in cross section, the triangle being isosceles in nature. The sides of the triangle correspond in length to the sides of opening 24 in sleeve 22. The apex of the triangle constitutes a right angle and its two end angles are 45 degree angles.

30 are not critical except that it is important that when two spring bars 39 are inserted into sleeve 22 in the manner shown in Figs. 3 and 5, a tight fit be provided between said spring bars and said sleeve to prevent accidental relative movement or displacement of said spring bars relative to said sleeve.

Fig. 4 is a cross sectional view showing how the ends of spring bar 30 are tapered off on their facing sides to provide a tapered space between them. See Figs 2 and 3.

of flexing and the resilience of said spring bars depending, necessarily, upon the material of which they are made. In the preferred form of this invention, a spring gold alloy is used, this being a precious metal and highly resistant to rust and corrosion, a hard metal, highly resistant to abrasion, and a resilient metal capable of spring flexing in the manner hereinafter described.

The tapered ends of spring bars 30 project into holes in sleeves 18 as Figs. 3 and 4 clearly show. The apexes of the spring bars snugly engage the apexes or corners of holes 20 as shown in Fig. 4. It will be recalled that sleeves 22 are secured to the arcuate arms 12 and 14 and that sleeves 18 are secured by means of cars 16 to wrist watch 10. When the arcuate arms are pivoted relative to the wrist watch, as indicated in Fig. 1, sleeves 22 will turn integrally with said arms. Since the spring bars are locked in place in sleeves 22, they will move integrally with said sleeves about the pivotal axis of arms 12 and 14. Sleeves 18, on the other hand, will remain stationary on the wrist watch,

This reduction in thickness at. the ends of spring bars 30 enables them to flex to a desired degree, the ease Consequently, spring bars 30 will engage in angular movement relative to sleeves 18. This will cause the apexes of the tapered ends of said spring bars to move out of the corners of holes 20 in sleeves 18 and to ride up on the sides of said holes 20. Since the sides are closer together than the corners, these tapered ends of the spring bars are caused to flex toward each other. This inward flexing of the tapered ends of the spring bars toward each other takes place against the inherent spring tension of said spring bars.

It will be observed in Fig. 4A that the apexes of the spring bars do not fully approach the center points of the sides of holes 20 on which they ride up. In other words, the relative angular movement between sleeves 22 and 18 has fallen short of degrees. It will be understood, therefore, that the spring action of these spring bars is in outward direction, urging sleeves 18 and 22 to return to their original positions and thereby to enable the tapered ends of the spring bars to resume their corner positions in holes 20. If the relative movement between sleeves 18 and 22 came to 45 degrees, the apexes of the tapered ends of spring bars 30 would be brought to the center portions of the sides of holes 20. The spring action of said spring bars would therefore be exerted in perpcndicular direction to the sides of holes 20 and the eflect would be to maintain said sleeves 1S and 22 in their 45 degree ofiset positions. Should these sleeves be turned relative to each other in excess of 45 degrees, once the apexes of spring bars 30 pass the center portions of the sides of holes 20, their spring action will be exerted in furtherance of such relative movement and such action will continue until said sleeves l8 and 22 move a full degrees relative to each other and the apexes of the tapered ends of spring bars 30 again occupy opposite corners in holes 26.

In the preferred form of this,invention, relative movement between the wrist watch and the arcuate arms should not attain 45 degrees. Limiting means is accordingly provided to prevent such relative arcuate movement beyond a predetermined point. This limiting means takes the form of a laterally projecting portion 44) on each sleeve 22. This laterally projecting portion engages an adjacent portion of the wrist watch when angular movement of the arcuate arm to which it is attached reaches the predetermined limit.

The foregoing is illustrative of a preferred form of this invention and as has above been indicated, variations and modifications may be incorporated therein within the broad spirit of the invention and the broad scope of the claims.

I claim:

1. A spring hinge having three members and means for pivotally connecting said members, said means comprising a pair of spring bars which define right angle isosceles triangles in cross section, said spring bars being reduced in thickness at their respective ends on their hypotenuse sides, one of said members comprising a central holder adapted to hold said spring bars at their central portions, said central holder having a square hole formed therein to accommodate the central portions of said spring bars and said spring bars being mounted therein with their respective hypotenuse sides, intermediate their reduced ends, in facing abutment with each other, their apexes being snugly disposed in opposite corners of said square hole, whereby said spring bars are fixed in said holder against relative movement, relative to each other and relative to said central holder, about the central axis of said square hole, said spring bars being longer than said central holder and projecting outwardly therefrom at their respective reduced ends, and the other two members comprising a pair of 1' end holders for said spring bars adapted to hold their re- U of said spring bars, their apexes being normally disposed in opposite corners of said square holes in the end holders, whereby said hinge members are pivotally connected to each other for pivotal movement relative to each other, such movement causing relative movement between the central holder and the end holders and causing the reduced ends of the spring bars to leave their respective corners in the square holes of the end holders and to ride up on the sides of said holes, being thereby flexed toward each other and exerting spring pressure upon the sides of said square holes in the end holders.

2. A spring hinge having three members and means for pivotally connecting said hinge members, said hinge members comprising a central holder and a pair of end holders, said central holder and said end holders being in axial alignment with each other and being'provided with registering holes formed therein which are square in cross section, and said connecting means comprising a pair of spring bars which define right angle isosceles triangles in cross section, said spring bars being reduced in thickness at their respective ends on their hypotenuse sides, said bars being substantially as long as the combined length of the central and end holders, and being disposed flat against each other with their respective hypotenuse sides, intermediate their reduced ends, in facing abutment with each other, said spring bars being mounted in the square holes of said central and end holders, the apexes of said spring bars being snugly disposed in opposite comers of the square hole in the central holder and being normally disposed in opposite corners of the square holes in the end holders, whereby relative angular movement between said central holder with its spring bars fixed therein and said end holders about about their common axis forces the reduced ends of said spring bars out of their respective corners in the square holes of the end holders and causes them to ride up on the sides of said square holes in the end holders.

3. A spring hinge in accordance with claim 2, wherein the reduced ends of the spring bars are tapered from their center portions to their end portions.

4. A spring hinge in accordance with claim 2, wherein the central and end holders are cylindrical in external shape, being substantially alike in diameter.

5. A spring hinge in accordance with claim 2, wherein a member is secured to the two end holders to fix them relative to each other and a stop member is provided on the central holder for engagement with the member to which the end holders are secured, thereby limiting the angular movement of said central and end holders relative to each other.

6. A spring hinge comprising a centrally disposed, internally square tubular member, a pair of internally square tubular end members disposed at the ends of said central tubular member, coaxially therewith, a pair of spring bars mounted in said central tubular member with their ends projecting into the tubular end members, said spring bars being triangular in cross section and being disposed face to face in said central tubular member, with their respective apexes lodged in opposite corners in said central tubular member, the apexes of the outwardly projecting ends of said spring bars being also lodged in opposite corners in said tubular end members, said outwardly projecting ends of the spring bars being reduced in thickness on their facing sides to space them from each other, whereby relative angular movement between the central tubular member and the tubular end members about their common longitudinal axis causes the apexes of the outwardly projecting ends of the spring bars to leave the corners of the tubular end members in which they were lodged, causing said outwardly projecting ends of the spring bars to flex toward each other.

References Cited in the file of this patent UNITED STATES PATENTS 

